Most popular files will be copyrighted, so if you choose not to download without a license, the files won't download It's up to each person to decide whether they wish to download copyrighted files...depends on your feelings about p2p, local laws etc

This might help.
License (click)

If you only want to download files which are legally shared, check out these threads for more info.
No license
Creative Commons - Wikipedia, the free encyclopedia
Creative Commons
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